Enterprise Systems

AN-2014 LMH2110 Evaluation Board (Rev. B)

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The evaluation board is designed to help the evaluation of the Texas Instruments LMH2110, which is a 45
dB Logarithmic RMS power detector particularly suited for accurate power measurement of modulated RF
signals that exhibit large peak-to-average ratios, that is, large variations of the signal envelope. Such
signals are encountered in W-CDMA and LTE cell phones. The RMS measurement topology inherently
ensures a modulation insensitive measurement.
The device has an RF frequency range from 50 MHz to 8 GHz. It provides an accurate, temperature and
supply insensitive, output voltage that relates linearly to the RF input power in dBm. The LMH2110's
excellent conformance to a logarithmic response enables an easy integration by using slope and intercept
only, reducing calibration effort significantly. The device operates with a single supply from 2.7V to 5V.
The LMH2110 has an RF power detection range from -40 dBm to 5 dBm and is ideally suited for use in
combination with a directional coupler. Alternatively a resistive divider can be used as well.
The device is active for EN = High, otherwise it is in a low power consumption shutdown mode. To save
power and prevent discharge of an external filter capacitance, the output (OUT) is high-impedance during
shutdown.